Web tension control



W 0. R. KADDELAND WEB TENSION CONTROL New: 19

Filed Jan. 5, 1938 5 Sheets-Sheet l INVENTOR. EHR IE TEN RM ADUELAND,

ATTORNEY?) 9, 940. c. R. KADDELAND 2 222,462

WEB TENSION CONTROL INVENTOF? v EHR IETEN RK AUUELAN 0.

ATTORNEY5 Nov. 19, 1940. Q R KADDELAND 2,222,462

WEB TENSION CONTROL BHRISTEN RLKADDELAND. BY fludaxwji ATTORNEYS Nov. 19, 1940. c. R. KADDELAND WEB TENSION CONTROL Filed Jan. 5, 1958 5 Sheets-Sheet 4 EHRISTEN REKADDELAND.

Nov; 19, 1940 c. R. KADDELAND Y Y A WEB TENSION CONTROL Filed Jan. 5, 1938 5 Sheets-Sheet 5 5 printing press or the like.

Patented Nov. 19, 1940 WEB TENSION CONTROL Christen R. Kaddeland, Shelton, Conn, assignor to Eiarris-Seybold-Potter Company, Cleveland, @hio, a corporation of Delaware Application January 5, 1938, Serial No. mates 8 Claims.

This invention relates to improvements in web tension controls, that is to say means for maintaining substantially constant the tension of a web being fed from a roll or other supply to a The invention, although of rather general application, is illustrated herein as applied to a printing press which acts upon sheets, provision being made in the machine for cutting the sheets from the web.

Under such circumstances it is highly desirable to maintain accurate control of the tension in order that the delivery of web material to the cutting knives may be at a constant rate. If the tension is permitted to change the amount of slippage 35 through the feeding rolls is correspondingly changed and the length of Web fed past the cutting knives for each operation of the latter is thereby changed, so that the length of the sheets removed from the web is not constant. 'The difficulty of holding the web tension constant is increased by the fact that the diameter and mass of the web roll, which constitutes the web supply, decreases constantly as the web supply is used up. The present invention is directed to means for "automatically controlling the tension of the web and maintaining it constant.

One of the objects of the invention therefore is the provision of means for establishing and maintaining a given tension of the web in a web feeding machine.

Another object is the provision of means for automatically varying the speed of rotation of the web roll as the tension of, the web tends to change to deliver an amount of web equal to that taken by the feeding rollers.

Another object is the provision of a web tension controlling device which shall have means in contact with the supply roll traveling at the same speed as the surface of the supply'roll and having substantially no slippage thereon.

A'further object is the provision of an improved change speed drive for the web roll in order to regulate the rate of removal of the web from the web supply.

Still another object of the invention is the provision of novel control means for the change speed drive, said control means being'responsive ley 33 is driven by a suitable source of power to small variations in the rate of release of the web, from the supply and to the resulting small variations in the tension of the web.

Other objectsand features of novelty will ap-' pear as I proceed with the description of that embodiment of the invention which, for the purposes of the present application, I have illus-' trated in the accompanying drawings, in which Fig. 1 is a diagrammatic elevational view of the invention applied to a multi-color printing press for printing on sheets which have been cut from a web.

Fig. 2 is a side elevation on a larger scale showing an embodiment of the invention arranged to regulate the tension in a web being fed to mech-, anism for cutting the web into sheets.

Fig. 3 is an end elevation looking in the direction of the arrows 3-3 of Fig. 2. i

Fig. 4 is a partial plan view on a still larger scale, the extent of the view being indicated by line 3-5 of Fig. 2.

Fig. 5 is a side elevation partly in section along the line 5-5 of Fig. 4. j

Fig. 6 is a side elevation of a part of the driving mechanism, viewed from the line B-6 of Fig. 3.

Fig. 7 is a diagrammatic view showing the mechanism which operates the electrical control device and the wiring diagram of that device.

In the drawings I0 is a base arranged to support a framework it of a web feeding and sheet cut-off mechanism which is illustrated as supplying sheets to a printing press l2 that operates upon, the cut-on sheets and delivers them by means of a conveyor l3 to a pile M of finished sheets. In the frame ll of the web feeder there is a web roll constituting the web supply, this roll being mounted upon a pair of spindles l6 carried in the frame. The roll I5 is shown in a fixed position relative to the frame, but a mounting similar to that illustrated and described in my copending application Serial No. 183,462, filed January 5, 1938, or any other suitable roll mounting may be employed if desired.

The web ll of paper or the like is led over a guide roller l8, around a pair of tensioning rollers l9 and 20, around the web pulling rollers 21 and 22 with which pressure rollers 23 and 24 cooperate, and between cut-ofi' cylinders 25 and 26. These cut-oil cylinders cut the web into sheets of desired length, and the sheetsare carried between tapes 2! and 28 to the feed rollers 29 and 30 of the press, and thence to the impression.cylinder 3! thereof.

A shaft 32 upon which is mounted a drive pulsuch as an electric motor (not shown) for driving the press. By means of the bevel gears 34 and 35, shaft 32 also drives a vertical shaft 36 which supplies the power for actuating the web feeding and sheet cut-off mechanism. This shaft is joined by sliding connection 3'! with a worm 38 whichmeshes with a worm wheel 39 (Fig. '4)

that is mounted inside a large casing 4|, see par spur gear 43. The gear 43 therefore turns with constant speed in synchronisrn with the operation of the printing press, its speed being dependent upon the speed of the motor which drives shaft 32.

As shown in Fig. 4, the shaft 42 upon which the worm wheel 39 and the spur gear 43 are mounted, also carries at its end a driving disk 44 which is formed with an off-set slotted guide 45 which engages a block 46 carried by a driven disk 41 that is keyed to the shaft, of the cutting cylinder 25. Cutting cylinders 25 and 26 are interconnected by means of spiral gears 25' and 26 respectively. It should also be noted that the casing 4| may be raised and lowered between gibs 49 'by means of a hand wheel 50, and that the angular position of the worm wheel 39 in relation to the driving worm 38 may be altered by raising or lowering the worm 38 by means of a hand wheel 5|. The construction of this mechanism and its purposes are all more fully disclosed in connection with my copending application, Serial No. 183,464, filed January 5, 1938; and do not have direct bearing on the present invention.

The constant speed gear 43 may beof any suitable size, dependent upon the length of sheet to be cut by the cut-off mechanism. It meshes with an idler gear 52, Fig. 6, which is mounted upon a swinging bracket 53 pivotally connected to the shaft 54, so that .the idler gear 52 may be meshed with gears of different sizes in place of the gear 43. Idler gear 52 meshes with a gear 55 keyed on the outer end of shaft 54, which shaft extends through the adjacent side frame member and has keyed on its inner end another gear 55 of the same diameter as gear 55. Gear 55' operates through idler gears 56 and 51 mounted upon studs in the frame of the machine, to drive the gear 59, also mounted on a stud in the frame. The gear 59 meshes with a gear 68 keyed to the upper web pulling roll 2|, and also with a gear' 6| keyed to the lower web pulling roll 22. These web pulling rollers 2| and 22 are rotatably mounted on stationary shafts 62 and 63 supported in the frame of the machine.

At each side of the machine close to the frame a pair of arms 64 are mounted on studs 65 for carrying the pressure roller 23 which is arranged to bear with some pressure against the web pulling rollers 2| and 22. Another similar pair of arms 66 mounted on studs 61 carry the other pressure roller 24 which bears against the roller 22.

The upper ends of the arms 64 and 66 on one or both sides of the machine are bifurcated to receive a spring rod 68 carrying a spring 69 which' is adjustable as to length. This spring tends to separate the upper ends of'the arms 64 and 66,- and consequently tends to press the pressure rollers'23 and 24 against their associated web pulling rollers. The spring rod 68 is provided at one end with a head 10. A shaft rotatably mounted in the frame of the machine carries at one.

outer end a handle 12, Fig. 2, by means of which the shaft may be turned through a portion of a revolution. This shaft is provided with a fiat portion in'the proper location to engage the head 19, and .a similarly formed surface on the upper end of the arm 66. It will be seen that rotation of the shaft H in either direction from. the position shown in Fig. 5 will cause separation of the head I0 and the upper end of lever 66 and that this separation, acting through the spring rod 68 and spring 69, will cause the pressure rollers 23 and 24 to be moved out of contact with the rollers 2| and 22. This manipulation of the levers 64 and 66 and the pressure rollers carried thereby is ordinarily used only during set-up periods.

around the top of roller 2|, between rollers 2| and 22, partiallyaround roller 23, between rollers 23 and 22, and thence downwardly between rollers 22 and 24. From this point it is directed between the cutting cylinders 25 and 26. It will be seen that thepressure of rollers 23 and 24 maintains the web of paper in firm contact with the surfaces of rollers 2| and 22 and that the latter, being driven by the constant speed gear 59 therefore exert a pull upon the web of paper H which tends to move it forward at substantially constant speed. 1

' It is a known fact however that the tension resulting from holding back the web of paper leaving the web supply varies to a certain extent the amount of paper measured off by a given number of rotations of the web pulling rollers' pulling rollers may remain constant in the operation of the machine. This mechanism, in which the present invention principally resides, will now be described. 8

Referring principally to Figs. 2,. 4 and 5, it will be seen that a spur gear 15, mounted on a stub shaft 16, meshes with idler 51, which is driven at constant speed.v Shaft 16 also carries a bevel gear 11 which meshes with a bevel gear 18 on the outer end of an input shaft 19 that is mounted in bearings carried by a tubular bracket 88 provided with feet which are bolted to the machine frame. On the opposite end of shaft 19 there is keyed a bevel gear 8| which constitutes oneelement of a differential gearing. A similar bevel gear 82 is keyed to an output shaft 83 on the opposite end of which is a bevel gear 84 that drives a large gear 85 keyed to a transverse shaft 86 which is mounted in anti-friction bearings 81 carried by the side membersof the machine frame. The shaft 83 is mounted in bearings at the ends of a tubular bracket 88 having feet bolted to the frame of the machine. A casing 89 encl'oses gears 84' and 85 and-is suitably supported by the machine frame. The shaft 86 carries a cylindrical pulley 99 over which run a series of spaced belts 9|. passes over an elongated pulley 92 journaled in bearings in the frame, as indicated in Fig. 2, while the other runs of the several belts extend over one side of the web roll l5, bearing upon the same over a considerable perimetric distance One run of each of these belts also with grooves on its sides fitting guide bars 96 that are carried in brackets 91 clamped to a transverse dove-tail supporting bar 98. The weights 95 move downwardly as the diameter of the roll I5 decreases, a lower position being indicated in dotted lines in Fig. 2, and they therefore tend to maintain a constant tension on the belts.

Returning now to the differential gear, by means of which the speed of rotation of the shaft 86 and the consequent speed of the belts Si is controlled, I provide a differential housing member 99 which has a rotative bearing I on one extremity of tubular bracket 80. This housing is provided with an'annular flange IOI to which is bolted a further housing member I02 provided with a hub which is revoluble on a bearing I03 carried by one end of tubular bracket 88. A shaft 8 is mounted in the differential housing intermediate the bevel gears 8I and 82, and this shaft with the housing itself constitutes a carrier for a pair of bevel pinions 9 which mesh I08 that is keyed to the output shaft of a geared head electric motor I09. The motor is supported upon a bracket IIO bolted to the frame,

I which bracket also supports a casing III that encloses and protects the worm and worm wheel.

Web tensioning roller I9 is carried by a shaft II2 which is mounted at its ends inarms II3 that swing about aligned stub shafts I I4 mounted in the side frame members. Rigid with the arms II 3 arecranks H5 formed at their outer ends with gear sectors I I6 which mesh with gears II1 keyed to a shaft II8 which is oscillatably mounted in the side members of the frame. The tensioning roller 20 is carried by shaft II9 that is mounted in the upper outer ends'of a pair of arms I20 which are mounted to swing upon stub shafts I2I mountedin the side frame members. Crank arms I22 rigid with arms I20 have gear sectors I23 on their free ends which mesh with gears II1 on the side thereof opposite the teeth which mesh with gear sectors H6.

The shaft H8 at one end carries a collar I24 to which is secured a bar I25 upon which is adjustably mounted a weight I26. Weight I26 provides a load upon shaft '8 which tends to turn that shaft anti-clockwise, as viewed in Figs. 2 and 5, and this motion when communicated through the gear H1 and gear, sectors H6 and I23 tends to swing the arms H3 and I20 away from each other so as to separate the tensioning rollers I9 and 20. This force is opposed by the pull of the tensioned Web which tends to draw the rollers I9 and 20 toward each other and thus to rotate the shaft H8 in the clockwise direction through the intermediacy of the sectors H6 and I23'and the gear II1.

In the present invention the small angular movements of the shaft II8 are utilized to bring about the variations in speed of the belt driving means necessary to maintain the web tension substantially constant. To this end, one extremity of shaft II8 carries a crank pin I21 to which is pivoted a rod I28, see particularly Fig. 7, that extends downwardly to a control box I28, Fig. 2, supported on a bracket carried by the machine frame. A bell crank lever I 29 is pivotally mounted at I30 in the control box,

and to one arm of this lever the rod I28 is connected. The other arm is pivotally connected with a link I3I which is connected to two lever arms [32 and I33, both pivoted at their upper ends to fixed supports. The lower ends of these levers are connected with carbon piles or the like constituting variable resistances I34 and I35. When the levers I32 and I33 move toward the left in Fig. 7 the variable resistances are both decreased, and when the levers move toward the right the resistances are increased. I36 represents the armature of motor I09, and I31 the field of that motor. Field I31 is bridged across lead wires I38 and I39 which are connected with line wires I40 and MI. The lead Wires I38 and I39 each extend to one end of the adjustable resistances I35 and I34, respectively. Between the lead wires I38 and I39 are conductors which for convenience I have illustrated as a parallelogram of four arms I42, I43, I44 and I45, the motor armature I36 being connected at its ends with the junction points of arms l42 and I43 on the one hand and I 44 and I45 on the other. In the arms I43 and I44 of the parallelogram I insert lamps or other resistances I46 and I41, these two resistances being preferably equal. The arms I 42 and I45 of the parallelogram include the variable resistances I35 and I34 respectively.

Operation.-The weight I26 is positioned on its supporting bar I25 at such a position, determined by experience, as will result in the desired tension for the web stock to be handled. The web is threaded through the machine as previously described and the press and feeder set in motion. Drive is thus transmitted through the differential gearing to the belts 9|, the latter moving at a speed to drive the web roll at a peripheral speed such as to release the web from the roll at the desired rate of travel of the web through the machine. The direction of rotation of the output shaft 83 will be opposite to the direction of rotation of the input shaft 19, and when the pinion carrier of the differential is standing still the speed of the shaft 83 will be the same as that of shaft 19. If the pinion carrier turns slowly in the same direction as shafts 19 rotates, the speed of shaft 83 will be slightly reduced. Contrariwise, if the pinion carrier is moved slowly in the opposite direction the speed of the shaft 83 will be slightly increased. The pulling rollers 2I and 22 are driven at a speed which tends to move the web through them at a rate slightly faster than it is released by the supply roll I 5. The tensioning rollers I9 and 20 place adrag on the web, and this in combination with the slightly lower peripheral speed of the web roll results in a tension on the web betweenthe pull-out rollers and the web roll. It is highly desirable to have this tension remain constant, because otherwise the slippage accompanying the action of rollers 2| and 22 would vary and the length of webing belts either up or down as conditions require.

This and other factors When the rate of release of the web from the supply becomes excessive thereby tending to decrease the tension in the web, the weight I26 moves the tensioning rollers I9 and 20 farther away from each other than their predetermined normal operating position, thus compensating variable resistances I34 and I35 to increase them.

When this occurs, the voltage across armature I36 by way of conductors I38, I42, I45, and I39 is changed, causing the motor to turn in a direction and at a rate which will retard belts 9|. This retards the rate of release of the web from theroll and causes a tendency toshorten the web, thus restoring the rollers I9 and 20 to their normal position. I

, On the other hand, if the rate of release is too slow, the tensioning rollers are drawn toward each other with the result that the shaft H8 is turned in the clockwise direction in Fig. '2 which serves to lower rod I28 and shift link I3I toward the left in Fig. 7. The lattermovement works through levers I32 and I33 to compress'the adjustable piles I34 and I35 to reduce their resistance. The voltage through armature I36 by way of conductors I42 and I45 is thereby altered in the opposite direction, with the effect that the speed of the motor I09 is correspondingly altered, or its direction changedas the case may be, to release the web of paper from the supply more rapidly. The increase in the amount of web released will in turn permit the rollers I9 and 20 to again assume their normal or equilibrium the speed of shaft 83 required for the proper rate of release of the web is the same as the speed of shaft 19 the resistance I35 will equal the resistance I41 and the resistance I34 will equal the resistance I46, when there will be no current passing through the armature I36, and the motor I09 will be idle. In every case where the motor is running. its operation may be such that the rotation of worm wheel I04 and the pinion carrier to which that worm wheel is attached is comparatively slow, as the ,gearing may be so proportioned that it is never necessary to operate shaft 83 at a speed greatly different from that of shaft I9 to obtain the desired speed of belts 9|. .The motor is prefEablyof the type whose speed is variable depending upon the voltage across the armature whereby the er'rtent of change of speed of the belts 9| may be approximately proportional to the difference between the amount of web released from the supply and the amount taken by the web driving rollers 2I and 22. The control isautomatic and accurate and operates within close limits. While I have shown electrical means for controlling the rate of web release, mechanical and hydraulic means, such as the well known reversible ratchet mechanism and variable speed reversible hydraulic motors with suitable valve mechanism, could be used for the same purpose and in. similar manner as the electric motor herein described. Thus the movement of shaft mechanism which would maintain the web tension by varying the speed of the web releasing means and include means whereby the tension may be varied at the will of the operator and tosuit various widths and kinds of web material.

Having thus described my invention I claim:

1. In mechanism for regulating web tension, means for rotatably supporting a web roll, means for advancing the web delivered from said roll, belt means adapted to engage the roll and control the delivery of web therefrom, means for driving said belt at the desired peripheral speed of the web roll, said driving means comprising a differential gearing having a'revoluble pinion carrier, and normally stationary positive driving means responsive to variations in web tension for revolving said pinion carrier, whereby the speed of said belt is changed to suit conditions, said last mentioned means comprising an electric motor and an electric circuit therefor containing variable resistance.

2. In mechanism for regulating web tension, means for rotatably supporting a web roll, means for advancing the web delivered from said roll, a shaft, means intermediate said roll and advancing means for turning said shaft in one direc-' tion or the other responsive to variations in web tension, belt means adapted to engage the roll and control the delivery ofv web therefrom, means for driving said .belt at a rate correspondingv to the peripheral speed of the web roll, said driving means comprising differential gearing having a pinion carrier, and normally stationary positive driving means responsive to the turning movement of said shaft for revolving said pinion carrier, whereby the speed of said belt is changed to suit conditions.

3. In mechanism for regulating web tension, means for rotatably supporting a web roll, means for advancing the web delivered from said roll, a shaft, means intermediate said roll and advancing means for turning said shaft in one direction or the other responsive to variations in .web ten-.

means for rotatably supporting a web roll, means for advancing the web delivered from said roll, belt means adapted to frictionally engage the roll and control the-delivery of web therefrom, tensioning rollers intermediate said advancing means and belt, means tending to maintain a predetermined relative adjustment of said rollers, means for driving said belt at a rate corresponding to the desired peripheral speed of the web roll, said driving means comprising differential gearing having a pinion carrier, and normally stationary positive driving means responsive to variationsin the relative adjustment of said tensioning rollers for imparting rotation to said pinion carrier, whereby a substantially constant web tension is maintained regardless of the diameter or condition of the web roll.

5. In mechanism for regulating web tension, a web roll, web advancing means spaced from said roll,web tensioning rollers located intermediate said advancing means and said roll over which said Web passes, an endless belt contacting said roll and adapted to have advancing or retarding efiects thereon so as to control the speed of rotation of the roll, driving means for said belt comprising diiTerential gearing including a rotatable pinion carrier, normally stationary positive driving means for rotating said carrier in order to vary the speed of said belt driving means, said carrier rotating means being independent of said driving means and being variable in speed, and automatic means responsive to variations in web tension for setting said carrier rotating means in operation and for varying the speed thereof.

6. In mechanism for regulating web tension, a web roll, web advancing means spaced from said roll, web tensioning rollers located intermediate said advancing means and said roll over which said web passes, an endless belt contacting said roll and adapted to have advancing or retarding effect thereon so as to control the speed of rotation of the roll, driving means for said belt comprising differential gearing including a rotatable pinion carrier, a normally stationary electric motor for rotating said carrier in order to vary the speed of said belt driving means, an electric circuit for said motor, and automatic means responsive to variations in Web tension and acting on said electric circuit for setting said motor in operation and varying its speed.

7. In mechanism for regulating web tension,

a web roll, web advancing means spaced from said roll, Web tensioning rollers located intermediate said advancing means and said roll over which said web passes, an endless belt contacting said roll and adapted to have advancing or retarding efiect thereon so as to control the speed of rotation of the roll, driving means for said belt comprising difierential gearing including a rotatable pinion carrier, a normally stationary electric motor for rotating said carrier in either direction in order to vary the speed of said driving means, an electric circuit for said motor, means in said circuit for reversing the motor and varying its speed in either direction, and automatic means responsive to variations in web tension for operating said motor reversing and speed changing means.

8. In mechanism for regulating web tension, means for rotatably supporting a web roll, means for advancing the webdelivered from said roll, I

belt means adapted to frictionally engage the roll and control the delivery of web therefrom, means for driving said belt atthe desired peripheral speed of the web roll,'said driving means comprising a differential gearing having a normally stationary revoluble pinion carrier, and means responsive to a given variation in web tension upwardly or downwardly for revolving said pinion carrier to an equal extent in one direction or the other during normal operation of said machine, whereby the speed of said belt is changed to suit conditions.

CHRISTEN R. KADDELAND. 

